Today this cleavage of opinion is much less apparent—indeed, it would scarcely be an exaggeration to say that it no longer exists. The change has come about, as all similar changes in scientific opinion must do, as the result of increased knowledge, During the past few years, several studies have been made on rats, mice and particularly calves, which have agreed in showing that only a minimal amount of damage is caused to the nutritive value of milk by low-temperature pasteurization. In addition, the occurrence of repeated outbreaks of milk-borne-disease, some of them accompanied by a relatively high mortality, has gone a long way to convince unprejudiced observers that tuberculosis is not by any means the only infection spread by milk to human beings.
1t is now recognized that cleanliness is not enough. The milk must also be safe—safe from the risk of spreading disease—if it is to be recommended more freely to supplement the inadequate or unbalanced dietary of certain sections of our population. In view of this increasing unanimity, it will probably be better to give a brief resume of the evidence on which our present conclusions are based rather than to set out the pros and cons of pasteurization, and thus create the illusion of a difference of opinion that now no longer exists. For reasons of space, discussion will be confined to the nutritional and hygienic aspects of cows' milk pasteurized by the official holding process (145°-150° F. for 30 minutes, followed by cooling! io 55* F. or below) and sold under licence. "Not until these two aspects are fully understood is it profitable fo consider the economic implications of compulsory pasteurization which play so large a part in practice in determining opposition to this measure.
Text read from the printed page and cleaned; old type leaves the occasional error.